/Engine/Plugins/Runtime/XRBase/Source/XRBase/Public/XRRenderTargetManager.h
Most implementations don't need to override this method and override GetActiveRenderBridge_GameThread instead.
virtual void UpdateViewportRHIBridge ( bool bUseSeparateRenderTarget, const class [FViewport](API\Runtime\Engine\FViewport) & Viewport, [FRHIViewport](API\Runtime\RHI\FRHIViewport) *const ViewportRHI )